At the present time, valves such as those employed in petroleum pipelines and the like are typically not manually operated. Rather, such valves are opened and closed utilizing valve operators. Valve operators for pipeline valves typically comprise an electric or fluid operated motor and a speed reducer which operate in combination to provide the output torque necessary to open and/or close the valve.
It has been determined that the torque necessary to open or close a valve is indicative of the operating condition of the valve. It is, therefore, useful to measure the torque necessary to operate the valve as a function of the operational status of the valve which in turn predicts the time remaining before the valve must be either serviced or replaced. The measurement of the torque necessary to operate the valve is a function of the positioning of the valve, with the highest torque requirement usually occurring at the start of the valve opening or closing operation.